please give me
Honorific request for an object. Used as a standalone polite imperative of くださる, often with を-marked object.
See also: 下さる
Please give me some water.
その本をください。
Please give me that book.
please do for me
Honorific request for an action. Attaches to the te-form of a verb or to a noun prefixed with お/ご. Extremely common in polite speech.
ちょっと待ってください。
Please wait a moment.
お名前を教えてください。
Please tell me your name.
ご確認ください。
Please check it.
ください is the modern, standard way to make a polite request; the suffix 給う (as in its imperative form 給え) serves the same function but sounds archaic and literary.
ください is a polite request form usable with anyone, while なさい is a plainer command typically used by a superior toward an inferior, such as a parent to a child.
ください is the polite way to ask for something, while ちょうだい is a casual, often feminine or child-like version of the same request.
くださる is the plain honorific verb meaning 'to give (to me)', while ください is its special imperative form used to make a polite request, so learners must remember to switch to ください (not くださる) when actually asking for something.
ください directly attaches to a verb to mean 'please do ~', while お願いいたします is a standalone humble formula often used with nouns, as in ご確認をお願いいたします.